1. Field of the Invention
The present invention relates to cleaning of drill pipe. More particularly, the present invention relates to a system for wiping, washing, and chemically treating drill string pipe as it is tripped out of the hole.
2. General Background
In the drilling of oil wells, the drill string is comprised of a plurality of sections of drill pipe threaded together end to end to make up the continuous string. From time to time, for various reasons, for example, to change the bit at the end of the string, the string must be raised or "tripped" out of the hole in order to have access to the drill bit. When the pipe is brought out of the hole, the various sections are removed from the string in view of the fact that often times the string may be thousands of feet long. During the process of drilling, it is necessary that the cuttings formed from the drill bit be removed from the hole, and that the well head be maintained under a certain hydrostatic pressure. Therefore, drilling mud is circulated down through a bore in the drill pipe, and is recirculated up the hole in the annular space between the drill pipe and the hole drilled by the bit. As the string is removed from the hole, the string will carry with it mud that is surrounding it as the drilling is going forth, therefore the result is that the mud, whether it be water based or oil based is lodged onto the surface of the drill pipe, as the pipe is brought up.
In the present state of the art, the roughneck on the rig washes down the pipe with a hose or the like in order to attempt to wash the mud from the surface so that mud is not carried up as the sections of the pipe are broken apart. This however, leads to (a) a loss in the valuable drilling mud that is utilized in the drilling process, and (b) casting off of mud on the rig floor or in the area of the blow-out preventers, which is not in keeping with the proper maintenance of the rig.
Therefore, there is a need in the art for an apparatus for system which would (a) clean excess mud from the surface of the drill pipe as it is tripped out of the hole, (b) cleaning of the surface following the removal of the mud, and (c) undertaking chemical treatment of the surface of the drill pipe to reduce the corrosive effects of the chemicals in the mud.
The following patents were obtained as a result of a search conducted, and are relevant to the art of cleaning of drill pipe.
______________________________________ PATENT NO. INVENTOR TITLE ______________________________________ 4,503,577 Fowler "Pipe And Hose Decontamination Apparatus" 4,600,444 Miner "Pipe End Area Cleaning System" 2,960,706 Dunham "Pile Cleaning And Treatment Device" 4,157,096 Miller, Jr. "Apparatus For Cleaning Threaded Pipe Ends" 4,011,617 Toelke, et al "Cleaner For Tubular Pin And Box Ends" 3,971,442 Scott "Method Of Cleaning Tubular Members On A Rig Floor" 4,457,366 Brown "Wiper Device For Stripping Fluid From Well Pipe" 4,406,331 Bentley "Pipe Wiper" ______________________________________